氧-取代的醯胺肟環加成反應的研究
No Thumbnail Available
Date
2017
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
本研究希望以amide oxime作為起始物進行環化反應來得到含氮雜環分子，研究初期希望以amide oxime與ethyl propiolate進行[3+2]環化加成反應得到五元環含氮雜環，卻意外的發現得到[3+3]環化加成產物2-phenylpyrimidin-4-one，但同時也發現，副反應ethyl propiolate進行[2+2+2]環化加成的反應速率大於[3+3]環化反應的速率，導致研究無法繼續下去。在篩選各種dipolarophic等同物後，發現使用enaminones化合物代替ethyl propiolate得到[3 + 2]環化產物imidazoles衍生物。接著進行後續反應條件優化探討，發現以O-substituteds amide oxime作為起始物與enaminones化合物在催化當量的鐵試劑條件下，成功合成出各種不同取代的imidazoles衍生物。
關鍵字：環化反應，含氮雜環，鐵試劑。
In this study, we used amide oxime as a starting material for cyclization reaction to obtain nitrogen-containing heterocyclic molecules. In the beginning of the study, we anticipated that the amide oxime and ethyl propiolate could undergo [3+2] cycloaddition to afford the five-membered ring nitrogen-containing heterocycls. However, we found that the reaction rate of the side reaction, [2+2+2] cycloaddition of ethyl propiolate to triethyl 1,3,5-benzenetricarboxylate, is greater than the rate of heterocycle formation, which surprisingly formed the six-membered heterocycle, 2-phenylpyrimidin-4-one, instead. After screening of various dipolarophile equivalents, we found that the use of the enaminones compound instead of ethyl propiolate gave the [3+2] cyclized product, and the cyclization adduct was found to be imidazole derivatives After the successful cyclization reaction, the subsequent optimization conditions were discussed. Finally, we found that using O-substituted amide oxime as the starting material reacted with enaminones in the catalytic amount of iron reagent can undergo [3+2] cycloaddition which successfully formed a variety of different substituted imidazole derivatives. Keywords : O-substituted amide oxime, cycloaddition, enaminones, imidazole.
In this study, we used amide oxime as a starting material for cyclization reaction to obtain nitrogen-containing heterocyclic molecules. In the beginning of the study, we anticipated that the amide oxime and ethyl propiolate could undergo [3+2] cycloaddition to afford the five-membered ring nitrogen-containing heterocycls. However, we found that the reaction rate of the side reaction, [2+2+2] cycloaddition of ethyl propiolate to triethyl 1,3,5-benzenetricarboxylate, is greater than the rate of heterocycle formation, which surprisingly formed the six-membered heterocycle, 2-phenylpyrimidin-4-one, instead. After screening of various dipolarophile equivalents, we found that the use of the enaminones compound instead of ethyl propiolate gave the [3+2] cyclized product, and the cyclization adduct was found to be imidazole derivatives After the successful cyclization reaction, the subsequent optimization conditions were discussed. Finally, we found that using O-substituted amide oxime as the starting material reacted with enaminones in the catalytic amount of iron reagent can undergo [3+2] cycloaddition which successfully formed a variety of different substituted imidazole derivatives. Keywords : O-substituted amide oxime, cycloaddition, enaminones, imidazole.
Description
Keywords
環化反應, 含氮雜環, 鐵試劑, O-substituted amide oxime, cycloaddition, enaminones, imidazole